Cleveland Family Study

18.5 Data Processing

18.5.1 Offline Automatic Analysis

This Compumedics program must be run prior to review of studies and final scoring to allow visualization of signals and graphic screens. Automatic sleep staging and respiratory scores are generated during the process. These data will not be used as final scores. (Offline Analysis detailed procedures are located in Family Polysomnography Manual).

18.5.2 Preliminary Review

After offline analysis of the record, the CP will then review each study to determine if overall quality is sufficient to be scored (passed/failed), and identify any potential medical alerts (defined as preliminary RDI >45). In addition, the CP will note any signal quality issues, possible monitor malfunctions, and recommendations for electrode replacements on the Receipt form.

Minimal criteria for study acceptability: The record must contain at least 4 hours of scorable EEG, oximetry and respiratory data (either airflow, thoracic or abdomen) between (edited) lights off and lights on (Total Time in Bed). Recorded time after final awakening will not contribute to this time. Two continuous blocks of scorable data, each at least 2 hours long are required to consider study acceptable for scoring.

18.5.3 Feedback of Data

After preliminary review by the CP is completed, the pass/fail status of the record is entered into the Receipts table database along with any comments and feedback notes regarding quality of the study and equipment troubleshooting.

The site coordinator is to verify that all information on the Record of Receipts is accurate and notify the SRC of any changes or corrections to be made. The Preliminary Study Quality Report should be made available to the field site technicians and quality issues reviewed and discussed.

18.5.4 Assignment of Studies to Scorers

Potential Medical Alerts - Studies identified as potential medical alerts will be triaged for immediate full scoring (within 48 hours of assignment to scorer). Once fully scored and determined to meet criteria for Medical Alerts (final RDI > 50, time in desaturation of <70% for >10% TST, or average heart rate > 150 BPM or <30 BPM for 2 minutes), a physician investigator will be asked to review the study. If the medical alert is ascertained, it will be logged into a Medical Alert Log and the site will receive the Participant Feedback Sleep Report and quality grades (QS form) with the regular weekly reports.

All remaining studies are scored based on date received. Bi-monthly review of scored studies by site by scorer is done to maintain equal distribution of studies from all sites among the scorers.

18.5.5 Quality Grades (QS Form; Sleep Quality Form)

The quality of each signal and overall study quality will be assessed at the time of scoring of the record. The Scorer will code each channel of information according to the duration of: i) scorable signals; ii) duration of artifact free signals during sleep, and iii) an overall QA grade to each study. The total duration of the study (from the edited lights off to the lights on) and the total duration of sleep will also be indicated. Scoring notes regarding staging, event identification, outliers, and specific physiologic signal issues are also recorded on the QS form.

All data contained in the QS form (quality grades and scoring notes) will be entered in the QS table database which contains only passed scored studies.

18.5.6 Scored Sleep Data

After full scoring, the scorer will generate:

• Family Participant Feedback Report (rtf format), contains summary sleep data. Data will be displayed in two parts (top/bottom of form), including the RDI (the number of apneas and hypopneas per hour of the sleep associated with a desaturation ≥ 3%), a summary of the desaturation profile, time in REM/Non-REM sleep, stage distributions, and the arousal index. The top half of the report will be used in the Participant Feedback Letters, and the bottom half (containing stage distribution and arousal indices) can be used in communications with local physicians.

• SAS report

• Completed QS form containing all quality grades and scoring notes.

The Sleep Data Summary Report and QS Report are e-mailed to each site on Mondays following the week scored (generally within 12 weeks of receipt of the SRC, except for studies which are triaged as possible Medical Alerts, which will be returned within one to two weeks of receipt).